This invention relates to ferromagnetic films and, more particularly, to ferromagnetic films having extremely small ferromagnetic particle size and to methods for production of said films.
Ferromagnetic films provide an excellent medium for recording of video, audio and digital information. Magnetic tapes and disks are widely used in the computer industry. Some computer users, such as Government agencies and insurance companies, require storage of huge amounts of data. To minimize the volume of the media for storing such quantities of data, high recording density is required. In the personal computer industry, the need exists for low cost, high density recording media.
Present day magnetic recording media utilize iron oxide particles dispersed in a polymer substrate. The iron oxide is in the form of needles 1 to 2 micrometers in length and is manufactured by a chemical process. The iron oxide is imbedded in the substrate by flowing the polymer over the surface and mixing in the particles. According to a newly developed technique, the iron oxide needles are arranged vertically in the substrate in order to increase recording density. However, this technique is not compatible with existing recording equipment. It has not been possible to produce iron oxide particles smaller than the 1 to 2 micrometer needles described above, due to limitations in the manufacturing process.
It is an object of the present invention to provide novel ferromagnetic films.
It is another object of the present invention to provide novel methods for production of ferromagnetic films.
It is yet another object of the present invention to provide novel ferromagnetic films for high density magnetic recording and methods of production thereof.
It is still another object of the present invention to provide methods of production of ferromagnetic films which achieve a high degree of uniformity and control of parameters.